As cuestas são definidas como uma forma de relevo dissimétrico, composta por uma vertente em declive íngreme de um lado e uma rampa em declive suave no reverso, decorrente da erosão diferencial das rochas. A região da Serra de São Pedro/SP, área de ocorrência de basaltos juro-cretáceos (topo da escarpa) e arenitos eólicos (escarpa e glacis) do Triássico ao Cretáceo Médio, consiste em uma das zonas mais típicas das cuestas na Bacia do Paraná, porém a configuração geometrizada do relevo da área, do sistema fluvial e até do baixo rio Piracicaba sugerem um controle tectônico das formas. Nesse sentido, o objetivo deste trabalho foi verificar o possível controle tectônico no relevo da Serra de São Pedro e do Baixo Piracicaba, focalizando a ação da Neotectônica, tendo como hipótese a existência de um forte controle das estruturas modernas sobre as formas. Os resultados mostraram que a atividade neotectônica na área é caracterizada principalmente pela atividade de falhas transcorrentes e normais subverticais WNW-ESE, W-E, NW-SE e NE-SW, ambas de pequeno rejeito e de impacto reduzido na morfologia do relevo. A influência das estruturas nas formas é mais intensa no sistema fluvial, comandando a dissecação do relevo de toda a área a partir de linhas estruturais que correspondem aos planos de juntas, grandes fraturamentos e falhas, ainda que a tectônica recente seja responsável pelo controle da direção apenas dos canais de 1º e 2º ordens. A Neotectônica condiciona ainda a formação de facetas triangulares na frente da escarpa da Serra de São Pedro, provoca perturbações de depósitos fluviais quaternários, anomalias no perfil longitudinal dos rios e inflexões dos interflúvios e canais de drenagem, além de pequenos basculamentos de blocos que causam a formação e degradação de terraços fluviais nos afluentes da margem direita do baixo Piracicaba. Essas informações são coerentes com os dados das estruturas medidas e materiais descritos em campo, bem como com as informações do contorno estrutural e dados geofísicos da área. Apesar do claro registro de neotectônica na região da Serra de São Pedro e do Baixo Piracicaba, os resultados demonstraram que a magnitude dessa atividade é reduzida e o seu impacto no relevo é pequeno, sendo que a configuração geomorfológica atual é mais influenciada por fatores litológicos, pela disposição das camadas sedimentares das rochas, pelos (paleo)climas e pela orientação/distribuição de estruturas tectônicas anteriores ao Neógeno, refutando assim a hipótese inicial do trabalho. / Cuestas are asymmetric landforms characterized by a steep slope along the plateau front and a gentle slope on its reverse, and they are interpreted as a relief formed by differential erosion of rocks. The São Pedro Ridge (Serra de São Pedro)/SP region, area with occurrence of juro-cretacic basalts (top of the ridge) and Triassic medium Cretaceous aeolian sandstone (scarp and glacis), is one of the most typical examples of the cuestas in the Paraná Basin. Although São Pedro Ridge is considered a cuesta, the geomorphological settings and the fluvial system (including the Lower Piracicaba River) of the area suggest a tectonic control on the landforms. Thus, the aim of this research was to verify a possible tectonic control on the São Pedro Ridge and Lower Piracicaba River landforms, emphasizing the Neotectonic influence. The hypothesis is that modern tectonics has a strong influence in the actual landforms. The results showed that the neotectonic activity in the study area is characterized mainly by sub-vertical strike-slip and normal faults WNW-ESE, WE, NW-SE and NE-SW, both with very small offsets and inconspicuous impact in the relief. The influence of the tectonic activity in the landforms is more intense in the fluvial system, controlling the relief dissection from joint planes, large fractures and faults, though modern tectonics is responsible for the control of the direction only of first and second order drainage channels. Neotectonics also controls the formation of triangular facets at the escarpment front of the São Pedro Ridge, faulting in quaternary fluvial deposits, anomalies in the longitudinal profiles of streams and changes in the direction of ridge lines and watercourses (river bends), as well as small block tilting which influences the formation and degradation of fluvial terraces of the Piracicaba right margin tributaries. These interpretations are coherent with the data set concerning the structures measured and materials characterized in the field, as well as with the information about the structural contour and geophysical data of the area. Despite the clear record of neotectonics in the São Pedro Ridge and Lower Piracicaba River region, the results demonstrated that the magnitude of the modern tectonic activity is small, and that the actual geomorphological configuration is more influenced by lithological factors, paleoclimates and the arrangement of sedimentary rock layers and pre-Neogene tectonic structures, thus refuting the initial hypothesis of this study.

Nesta pesquisa, em 14 pacientes da Clínica de Prótese Total da Faculdade de Odontologia da Universidade de São Paulo, foi realizada a avaliação da retenção de prótese total bimaxilar em função das características da área basal por três avaliadores clínicos experientes e calibrados. Foram avaliadas as retenções vertical anterior, laterais direita e esquerda e póstero-anterior e as características da área basal: forma, tamanho, altura e tipo do rebordo e a consistência da fibromucosa. Por se tratarem de opiniões, os dados foram transformados em escores e submetidos à análise de variância não paramétrica com o teste KRUSKAL-WALLIS e paramétrica com o teste ANOVA. Concluiu-se que, na maxila, a retenção das próteses totais novas foi influenciada positivamente pelo tipo rebordo paralelo e pela consistência resiliente da fibromucosa, enquanto na mandíbula influenciaram o tamanho médio e a forma oval. As opiniões sobre a retenção e o grau de satisfação entre os avaliadores e os pacientes foram as mesmas. / In this research, a evaluation of the retention of bimaxilar complete denture in function of the characteristics of the basal area by three calibrated experienced clinician was accomplished in 14 patients of the Odontology College of the University of São Paulo. The anterior vertical retention, right lateral retention, left lateral retention, posteroanterior retention and rigde shape, ridge size, rigde height, ridge type and the fibromucosa consistency were evaluated. Because of they are opinions, the data were trans formed in scores and submitted to the no parametric variance analysis with the KRUSKAL-WALLIS and ANOVA parametric tests. Conclusion, in the maxilla, the retention of the new complete denture, was positively influenced by the parallel rigde type and by the resilient consistency of the fibromucosa, while in the mandible, the decisive factors of the retention were the medium size of the rigde and the oval shape of this. The opinions about the retention and the level of satisfaction had been the same among the appraisers and patients.

Three gastropods occupy a range of habitats along gradients in hydrothermal flux at Juan de Fuca Ridge vents. I examined how these species co-exist and identified mechanisms driving their abundances. First, I measured temperatures and spatial patterns in adult densities of the three species at three distances from vents to test if thermal regime relates to their habitat selection. Lepetodrilus fucensis and Depressigyra globulus were most dense in-vent (0-25 cm) at variable temperatures (10+5°C): 2100 and 240 incl. dm -2 (respectively). Provanna variabilis was most abundant far-vent (51-75 cm: 60 ind. dm 2) at stable temperatures (3±0.5°C). Thermal conditions are key in their habitat selection: behavioural experiments showed that these gastropods select fluid temperatures<18°C. L.fucensis and D. globulus preferred 5-15°C, while P. variabilis preferred 4-12°C. The next studies sought to explain how Lepetodrilus fucensis reaches order of magnitude higher densities in comparison to other gastropods. First. I quantified L. fucensis recruitment and sex ratio patterns to identify innovative life history traits. I meaured size structure and density at in- and far-vent locations. Early postlarval juveniles occupied far-vent at remarkable densities (2419 ind. dm-2). To test for sex ratio biases, I sexed animals from different habitats and sizes. Populations nearest vents hosted the largest females (>6.0 mm), while peripheral habitats were male-biased. A transplant experiment showed that female survivorship and gonad fullness were significantly lower than males in far-vent locations. Sex ratio biases are driven by two mechanisms: females maximize their reproductive output by selecting optimal habitats and suffer relatively higher mortality in low flux. Next, I hypothesized that the Lepetodrilus fucensis gill symbiosis is a key adaptation. I used multiple approaches to determine if the prevalence of the association and relationship to the limpets condition support this hypothesis. FISH probes specific to the 16S rRNA molecule of a gamma-Proteobacteria hybridized where bacteria were present. Direct sequencing using symbiont-specific primers gave a single unambiguous sequence. indicating high specificity. Light and TEM micrographs of gill tissue from a range of species also showed that the symbiosis is ubiquitous. In addition, the gills of in-vent animals had high surface area. dense symbiont populations and healthy tissues, while far-vent animals showed the reverse trend, suggesting that the symbiosis benefits L. fucensis. Carbon fixation by gill tissues was stimulated by inorganic sulfide and related to the abundance of bacteria on the gill. These data indicate a persistent and specific symbiosis that is dependent on access to sulphide. I further examined feeding by Lepetodrilus fucensis to determine if the bacteria contribute to their host's nutrition. The morphology of feeding structures were compared among Lepetodrilus species. L. fucensis exhibited specialized features: the gill is enlarged. the lamellae are free of the mantle. do not narrow and are stabilized by ciliary junctions. The radula and stomach of L. fucensis are also reduced. Shipboard observations confirmed suspension feeding by L. fucensis. In addition, the symbiont may be ingested because its phylotype was well-represented in food material on the gill. The limpet's morphological specializations are consistent with dependence on suspension feeding and/or symbiont farming; however, L. fucensis also grazes. a mechanism likely important in peripheral locations. Lepetodrilus fucensis populations are partitioned by size and sex along environmental gradients near vents. Peripheral populations are dominated by recruits and adults tend to be male: grazing is likely their primary feeding mode. Larger animals form stacks in venting fluids and are female-biased. These populations access suspended particles for food and sulphide, which generates dense symbiont populations for ingestion. Multiple feeding modes sustain high L. fucensis densities in a space-limited environment and may be an innovative strategy that drives its remarkable abundances.

Stream capture is a major driver of the retreat of the Blue Ridge Escarpment, but timescales of capture are not well understood. This study examines stream sediment geochemistry to establish a set of sediment source fingerprints which can be used to identify and date the capture of the Tallulah River. Statistical analyses show significant differences in U, Th, and certain REE enrichment. These differences result from variations in bedrock along the lengths of each river and a shift in relative stream powers after capture to favor mobilization or deposition of heavy elements. The observed differences should be sufficient to identify where Tallulah sediment appears in floodplains of the capturing Tugaloo River, facilitating future dating of the capture event. Understanding the timing of river capture will provide insight into the ongoing reshaping and redistribution of river systems and interactions of geomorphic processes in the continuing evolution of the southern Appalachian Mountains.

Multiple linear regression model plays a key role in statistical inference and it has extensive applications in business, environmental, physical and social sciences. Multicollinearity has been a considerable problem in multiple regression analysis. When the regressor variables are multicollinear, it becomes difficult to make precise statistical inferences about the regression coefficients. There are some statistical methods that can be used, which are discussed in this thesis are ridge regression, Liu, two parameter biased and LASSO estimators. Firstly, an analytical comparison on the basis of risk was made among ridge, Liu and LASSO estimators under orthonormal regression model. I found that LASSO dominates least squares, ridge and Liu estimators over a significant portion of the parameter space for large dimension. Secondly, a simulation study was conducted to compare performance of ridge, Liu and two parameter biased estimator by their mean squared error criterion. I found that two parameter biased estimator performs better than its corresponding ridge regression estimator. Overall, Liu estimator performs better than both ridge and two parameter biased estimator.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

A transmission line format is presented which takes the form of a Multilayer Ridged Substrate Integrated Waveguide, for which signal energy is transmitted within standard PCB substrates, within a wave-guiding structure formed from conducting tracks in the horizontal plane and arrays of through-plated vias in the vertical plane. The Substrate Integrated Waveguide (SIW) is a recent development into which research is so far concentrated on single-layer rectangular variants which, like traditional rectangular waveguide, are amenable to analytic computation of the cutoff eigenvalues. Recent publications have offered empirically-derived relationships with which a Substrate Integrated Waveguide can be analysed by equivalence of the horizontal dimensions with a conventional waveguide, allowing such structures to be designed with minimal effort. We propose a ridged form of this structure, in which multiple PCB layers are stacked to obtain the desired height and the published equivalent width is used to obtain the horizontal dimensions. The proposed structure combines the increased bandwidth of ridged waveguide with SIW’s greatly reduced cost of manufacture and integration, relative to conventional waveguide, and improved power handling capacity and loss susceptibility relative to microstrip. Ridged variants have not yet been studied in the literature, however, in part because the eigenspectrum can not be obtained analytically. We thus present a semi-analytical software model with which to synthesise and analyse the cutoff spectrum in ridged Substrate Integrated Waveguide, verified by comparison with analytical solutions, where they exist, simulation in finite-element software and a physical prototype. Agreement with simulated and measured results is within 1 % in certain subsets of the parameter space and 11 % generally, and individual results are returned in times of the order of seconds. We use the model to analyse the relationship between geometry and frequency response, constructing an approximating function for the early modes which is significantly faster, such that think it can be used for first-pass optimisation. A range of optimal parameters are presented which maximise bandwidth within anticipated planar geometric constraints, and typical design scenarios are explored.

The Endeavour Ridge is a segment of the Juan de Fuca Ridge, an active spreading centre which lies off western North America between the Pacific and Juan de Fuca plates. This segment is a bathymetric high and a site of hydrothermal activity—both characteristics suggest an underlying heat source such as an axial magma chamber which is associated with crustal generation. To investigate the creation and evolution of oceanic crust, a detailed refraction survey was carried out over the Endeavour Ridge in the fall of 1985. As a component of this survey, a diamond-shaped array consisting of eight OBS along a 20-km line across the ridge and two OBS placed along it at distances of 10 km on either side of the cross-ridge line was deployed to define the shallow crustal structure near and beneath the ridge, especially the possible existence of an axial magma chamber. Airgun shots at 0.2 km intervals along ~300 km of profiles provide conventional reversed and unreversed refraction lines as well as multiple full azimuthal coverage of the region. Travel-time and amplitude data from fifteen in-line airgun profiles recorded on the inner array were forward modelled using an algorithm based on asymptotic ray theory with a starting model obtained from a concurrent study. Two-dimensional models were constructed and then combined to obtain the three-dimensional structure of the region. These models consist of four layers, with the average model correlating well to the classic model of oceanic crust. Layer 2A averages 0.40 km in thickness and has velocities of 2.6 km/s and 2.8 km/s at the top and bottom of the layer, respectively. To achieve such a low velocity, Layer 2A must consist of highly fractured vesicular basalts. A sharp velocity increase to 4.8 km/s marks the transition to Layer 2B. This velocity discontinuity is also visible as a reflector on a. multichannel reflection line obtained through the centre of the study region and is caused by an abrupt decrease in porosity. Layer 2B averages 0.67 km in thickness, has a velocity of 5.4 km/s at its base and consists of less fractured pillow basalts and sheet flows. The Layer 2B-Layer 2C interface is a velocity increase to 5.8 km/s and is the pillow basalt-sheeted dike contact. A small velocity increase from 6.3 to 6.5 km/s delineates the base of the 0.95 km-thick Layer 2C which is the boundary between the sheeted dikes and cumulate gabbros in Layer 3. Layer 3 has the lowest velocity gradient (0.30 s⁻¹) and a velocity of 7.3 km/s at 4.65 km below the seafloor, the maximum depth constrained by the modelling. Lateral heterogeneities on the scale of 2-3 km are superimposed on this basic velocity structure. These heterogeneities are effects of porosity changes, differential pressure changes, and alteration caused by hydrothermal circulation. Layer 2A thins and increases in velocity away from the ridge; ridge-parallel cracks create a velocity anisotropy of ~10-25%, the faster direction parallel to the ridge. Velocities within Layers 2B and 2C also increase by 0.1 km/s away from the axis of the ridge. Layer 3 velocities decrease by 0.1 km/s for arrivals travelling under the ridge. Increased Layer 2 velocities at the ridge crest reveal high lateral velocity constrasts in very young crust, but within 0.03 Ma the oceanic crust at the ridge has matured to the off-ridge structure. No firm evidence exists for a large magma chamber under Endeavour Ridge. Although the bathymetric high and high-temperature hydrothermal discharges are evidence for a magma chamber, the lack of recent sheet flows at the ridge crest and the presence of a rift along the crest indicate the magma chamber is waning and must be of a size (<1 km in width) not resolvable by seismic refraction data. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

In the Ridge and Valley physiographic province, knobs stand out as anomalous landforms embedded within a region of long, parallel ridges and valleys. In northeastern Tennessee, knobs are associated with the Sevier shale. Well-drained, acidic, channery loam Montevallo soils cover uplands of these knobs. A flora of the Sevier shale knobs of northeastern Tennessee identified 265 taxa in 57 plant families of which 13.6% were exotic and three were state listed (Berberis canadensis, Ruellia purshiana, Silene caroliniana var. pensylvanica). Many taxa had rarely or never been collected in northeastern Tennessee. The flora of the Sevier shale knobs was most similar to dolomite and limestone barrens of southwestern Virginia but among the species rarely collected in northeastern Tennessee, the greatest number was shared with floras of the Sequatchie Valley, middle Tennessee cedar glades, and barrens of the Tennessee eastern Highland Rim.

In the development of materials, the understanding of their properties is crucial. For magnetic materials, magnetism is an apparent property that needs to be accounted for. There are multiple factors explaining the phenomenon of magnetism, one being the effect of vibrations of the atoms on longitudinal spin fluctuations. This effect can be investigated by simulations, using density functional theory, and calculating energy landscapes. Through such simulations, the energy landscapes have been found to depend on the magnetic background and the positions of the atoms. However, when simulating a supercell of many atoms, to calculate energy landscapes for all atoms consumes many hours on the supercomputer. In this thesis, the possibility of using machine learning models to accelerate the approximation of energy landscapes is investigated. The material under investigation is body-centered cubic iron in the paramagnetic state at 1043 K. Machine learning enables statistical predictions to be made on new data based on patterns found in a previous set of data. Kernel ridge regression is used as the machine learning method. An important issue when training a machine learning model is the representation of the data in the so called descriptor (feature vector representation) or, more specific to this case, how the environment of an atom in a supercell is accounted for and represented properly. Four different descriptors are developed and compared to investigate which one yields the best result and why. Apart from comparing the descriptors, the results when using machine learning models are compared to when using other methods to approximate the energy landscapes. The machine learning models are also tested in a combined atomistic spin dynamics and ab initio molecular dynamics simulation (ASD-AIMD) where they were used to approximate energy landscapes and, from that, magnetic moment magnitudes at 1043 K. The results of these simulations are compared to the results from two other cases: one where the magnetic moment magnitudes are set to a constant value and one where they are set to their magnitudes at 0 K. From these investigations it is found that using machine learning methods to approximate the energy landscapes does, to a large degree, decrease the errors compared to the other approximation methods investigated. Some weaknesses of the respective descriptors were detected and if, in future work, these are accounted for, the errors have the potential of being lowered further.